Vacuum adiabatic body and refrigerator

ABSTRACT

A vacuum adiabatic body may include: a first plate member; a second plate member; a sealing part sealing the first plate member and the second plate member to provide a third space; a supporting unit maintaining the third space; a heat resistance unit at least including a conductive resistance sheet capable of resisting heat conduction flowing along a wall for the third space to decrease a heat transfer amount between the first plate member and the second plate member; and an exhaust port through which a gas in the third space is exhausted. A side frame may be fastened to the conductive resistance sheet and the second plate member, and the side frame is fastened to an edge portion of the second plate member. Accordingly, the formation of dews may be prevented and an adiabatic effect may be improved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. Application No.17/114,950, filed Dec. 8, 2020, which is a Divisional Application ofU.S. National Stage Application No. 15/749,139, filed Jan. 31, 2018under 35 U.S.C. §371 of PCT Application No. PCT/KR2016/008502, filedAug. 2, 2016, which claims priority to Korean Patent Application No.10-2015-0109723, filed Aug. 3, 2015, whose entire disclosures are herebyincorporated by reference.

BACKGROUND 1. Field

The present disclosure relates to a vacuum adiabatic body and arefrigerator.

2. Background

A vacuum adiabatic body is a product for suppressing heat transfer byvacuumizing the interior of a body thereof. The vacuum adiabatic bodycan reduce heat transfer by convection and conduction, and hence isapplied to heating apparatuses and refrigerating apparatuses. In atypical adiabatic method applied to a refrigerator, although it isdifferently applied in refrigeration and freezing, a foam urethaneadiabatic wall having a thickness of about 30 cm or more is generallyprovided. However, the internal volume of the refrigerator is thereforereduced.

In order to increase the internal volume of a refrigerator, there is anattempt to apply a vacuum adiabatic body to the refrigerator.

First, Korean Patent No. 10-0343719 (Reference Document 1) of thepresent applicant has been disclosed. According to Reference Document 1,there is disclosed a method in which a vacuum adiabatic panel isprepared and then built in walls of a refrigerator, and the exterior ofthe vacuum adiabatic panel is finished with a separate molding asStyrofoam (polystyrene). According to the method, additional foaming isnot required, and the adiabatic performance of the refrigerator isimproved. However, manufacturing cost is increased, and a manufacturingmethod is complicated. As another example, a technique of providingwalls using a vacuum adiabatic material and additionally providingadiabatic walls using a foam filling material has been disclosed inKorean Patent Publication No. 10-2015-0012712 (Reference Document 2).According to Reference Document 2, manufacturing cost is increased, anda manufacturing method is complicated.

As another example, there is an attempt to manufacture all walls of arefrigerator using a vacuum adiabatic body that is a single product. Forexample, a technique of providing an adiabatic structure of arefrigerator to be in a vacuum state has been disclosed in U.S. Pat.Laid-Open Publication No. US 2004/0226956 A1 (Reference Document 3).

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

FIG. 1 is a perspective view of a refrigerator according to anembodiment.

FIG. 2 is a view schematically showing a vacuum adiabatic body used in amain body and a door of the refrigerator.

FIG. 3 is a view showing various embodiments of an internalconfiguration of a vacuum space part.

FIG. 4 is a view showing various embodiments of conductive resistancesheets and peripheral parts thereof.

FIG. 5 is a view illustrating in detail a vacuum adiabatic bodyaccording to an embodiment.

FIG. 6 illustrates temperature distribution curves with respect topositions of a conductive resistance sheet.

FIG. 7 is an exploded perspective view of a vacuum adiabatic bodyaccording to an embodiment.

FIG. 8 illustrates graphs showing changes in adiabatic performance andchanges in gas conductivity with respect to vacuum pressures by applyinga simulation.

FIG. 9 illustrates graphs obtained by observing, over time and pressure,a process of exhausting the interior of the vacuum adiabatic body when asupporting unit is used.

FIG. 10 illustrates graphs obtained by comparing vacuum pressures andgas conductivities.

FIG. 11 is a partial sectional view of a vacuum adiabatic body accordingto an embodiment.

FIG. 12 is a view comparing volume performances of an external door of adoor-in-door refrigerator.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings.

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings that form a part hereof,and in which is shown by way of illustration specific preferredembodiments in which the disclosure may be practiced. These embodimentsare described in sufficient detail to enable those skilled in the art topractice the disclosure, and it is understood that other embodiments maybe utilized and that logical structural, mechanical, electrical, andchemical changes may be made without departing from the spirit or scopeof the disclosure. To avoid detail not necessary to enable those skilledin the art to practice the disclosure, the description may omit certaininformation known to those skilled in the art. The following detaileddescription is, therefore, not to be taken in a limiting sense.

In the following description, the term ‘vacuum pressure’ means a certainpressure state lower than atmospheric pressure. In addition, theexpression that a vacuum degree of A is higher than that of B means thata vacuum pressure of A is lower than that of B.

FIG. 1 is a perspective view of a refrigerator according to anembodiment.

Referring to FIG. 1 , the refrigerator 1 includes a main body 2 providedwith a cavity 9 capable of storing storage goods and a door 3 providedto open/close the main body 2. The door 3 may be rotatably or movablydisposed to open/close the cavity 9. The cavity 9 may provide at leastone of a refrigerating chamber and a freezing chamber.

Parts constituting a freezing cycle in which cold air is supplied intothe cavity 9. Specifically, the parts include a compressor 4 forcompressing a refrigerant, a condenser 5 for condensing the compressedrefrigerant, an expander 6 for expanding the condensed refrigerant, andan evaporator 7 for evaporating the expanded refrigerant to take heat.As a typical structure, a fan may be installed at a position adjacent tothe evaporator 7, and a fluid blown from the fan may pass through theevaporator 7 and then be blown into the cavity 9. A freezing load iscontrolled by adjusting the blowing amount and blowing direction by thefan, adjusting the amount of a circulated refrigerant, or adjusting thecompression rate of the compressor, so that it is possible to control arefrigerating space or a freezing space.

FIG. 2 is a view schematically showing a vacuum adiabatic body used inthe main body and the door of the refrigerator. In FIG. 2 , a mainbody-side vacuum adiabatic body is illustrated in a state in which topand side walls are removed, and a door-side vacuum adiabatic body isillustrated in a state in which a portion of a front wall is removed. Inaddition, sections of portions at conductive resistance sheets areprovided are schematically illustrated for convenience of understanding.

Referring to FIG. 2 , the vacuum adiabatic body includes a first platemember (or first plate) 10 for providing a wall of a low-temperaturespace, a second plate member (or second plate) 20 for providing a wallof a high-temperature space, a vacuum space part (or vacuum space orcavity) 50 defined as a gap part (or gap or space) between the first andsecond plate members 10 and 20. Also, the vacuum adiabatic body includesthe conductive resistance sheets 60 and 63 for preventing heatconduction between the first and second plate members 10 and 20. Asealing part (or seal or sealing joint) 61 for sealing the first andsecond plate members 10 and 20 is provided such that the vacuum spacepart 50 is in a sealing state. When the vacuum adiabatic body is appliedto a refrigerating or heating cabinet, the first plate member 10 may bereferred to as an inner case, and the second plate member 20 may bereferred to as an outer case. A machine chamber 8 in which partsproviding a freezing cycle are accommodated is placed at a lower rearside of the main body-side vacuum adiabatic body, and an exhaust port 40for forming a vacuum state by exhausting air in the vacuum space part 50is provided at any one side of the vacuum adiabatic body. In addition, apipeline 64 passing through the vacuum space part 50 may be furtherinstalled so as to install a defrosting water line and electric lines.

The first plate member 10 may define at least one portion of a wall fora first space provided thereto. The second plate member 20 may define atleast one portion of a wall for a second space provided thereto. Thefirst space and the second space may be defined as spaces havingdifferent temperatures. Here, the wall for each space may serve as notonly a wall directly contacting the space but also a wall not contactingthe space. For example, the vacuum adiabatic body of the embodiment mayalso be applied to a product further having a separate wall contactingeach space.

Factors of heat transfer, which cause loss of the adiabatic effect ofthe vacuum adiabatic body, are heat conduction between the first andsecond plate members 10 and 20, heat radiation between the first andsecond plate members 10 and 20, and gas conduction of the vacuum spacepart 50.

Hereinafter, a heat resistance unit provided to reduce adiabatic lossrelated to the factors of the heat transfer will be provided. The heatresistance unit may also be referred to as a thermal insulator, or thelike, that provides one or more structural means configured to providethermal insulation. Meanwhile, the vacuum adiabatic body and therefrigerator of the embodiment do not exclude that another adiabaticmeans is further provided to at least one side of the vacuum adiabaticbody. Therefore, an adiabatic means using foaming or the like may befurther provided to another side of the vacuum adiabatic body.

FIG. 3 is a view showing various embodiments of an internalconfiguration of the vacuum space part.

First, referring to FIG. 3 a , the vacuum space part 50 is provided in athird space having a different pressure from the first and secondspaces, preferably, a vacuum state, thereby reducing adiabatic loss. Thethird space may be provided at a temperature between the temperature ofthe first space and the temperature of the second space. Since the thirdspace is provided as a space in the vacuum state, the first and secondplate members 10 and 20 receive a force contracting in a direction inwhich they approach each other due to a force corresponding to apressure difference between the first and second spaces. Therefore, thevacuum space part 50 may be deformed in a direction in which it isreduced. In this case, adiabatic loss may be caused due to an increasein amount of heat radiation, caused by the contraction of the vacuumspace part 50, and an increase in amount of heat conduction, caused bycontact between the plate members 10 and 20.

A supporting unit (support) 30 may be provided to reduce the deformationof the vacuum space part 50. The supporting unit 30 includes bars 31.The bars 31 may extend in a direction substantially vertical to thefirst and second plate members 10 and 20 so as to support a distancebetween the first and second plate members 10 and 20. A support plate 35may be additionally provided to at least one end of the bar 31. Thesupport plate 35 connects at least two bars 31 to each other, and mayextend in a direction horizontal to the first and second plate members10 and 20. The support plate 35 may be provided in a plate shape, or maybe provided in a lattice shape such that its area contacting the firstor second plate member 10 or 20 is decreased, thereby reducing heattransfer. The bars 31 and the support plate 35 are fixed to each otherat at least one portion, to be inserted together between the first andsecond plate members 10 and 20. The support plate 35 contacts at leastone of the first and second plate members 10 and 20, thereby preventingdeformation of the first and second plate members 10 and 20. Inaddition, based on the extending direction of the bars 31, a totalsectional area of the support plate 35 is provided to be greater thanthat of the bars 31, so that heat transferred through the bars 31 can bediffused through the support plate 35.

A material of the supporting unit 30 may include a resin selected fromthe group consisting of PC, glass fiber PC, low outgassing PC, PPS, andLCP so as to obtain high compressive strength, low outgassing and waterabsorptance, low thermal conductivity, high compressive strength at hightemperature, and excellent machinability.

A radiation resistance sheet 32 for reducing heat radiation between thefirst and second plate members 10 and 20 through the vacuum space part50 will be described. The first and second plate members 10 and 20 maybe made of a stainless material capable of preventing corrosion andproviding a sufficient strength. The stainless material has a relativelyhigh emissivity of 0.16, and hence a large amount of radiation heat maybe transferred. In addition, the supporting unit 30 made of the resinhas a lower emissivity than the plate members, and is not entirelyprovided to inner surfaces of the first and second plate members 10 and20. Hence, the supporting unit 30 does not have great influence onradiation heat. Therefore, the radiation resistance sheet 32 may beprovided in a plate shape over a majority of the area of the vacuumspace part 50 so as to concentrate on reduction of radiation heattransferred between the first and second plate members 10 and 20. Aproduct having a low emissivity may be preferably used as the materialof the radiation resistance sheet 32. In an embodiment, an aluminum foilhaving an emissivity of 0.02 may be used as the radiation resistancesheet 32. Since the transfer of radiation heat cannot be sufficientlyblocked using one radiation resistance sheet, at least two radiationresistance sheets 32 may be provided at a certain distance so as not tocontact each other. In addition, at least one radiation resistance sheetmay be provided in a state in which it contacts the inner surface of thefirst or second plate member 10 or 20.

Referring to FIG. 3 b , the distance between the plate members ismaintained by the supporting unit 30, and a porous material 33 may befilled in the vacuum space part 50. The porous material 33 may have ahigher emissivity than the stainless material of the first and secondplate members 10 and 20. However, since the porous material 33 is filledin the vacuum space part 50, the porous material 33 has a highefficiency for resisting the radiation heat transfer.

In this embodiment, the vacuum adiabatic body can be manufacturedwithout using the radiation resistance sheet 32.

Referring to FIG. 3 c , the supporting unit 30 maintaining the vacuumspace part 50 is not provided. Instead of the supporting unit 30, theporous material 33 is provided in a state in which it is surrounded by afilm 34. In this case, the porous material 33 may be provided in a statein which it is compressed so as to maintain the gap of the vacuum spacepart 50. The film 34 is made of, for example, a PE material, and may beprovided in a state in which holes are formed therein.

In this embodiment, the vacuum adiabatic body can be manufacturedwithout using the supporting unit 30. In other words, the porousmaterial 33 can serve together as the radiation resistance sheet 32 andthe supporting unit 30.

FIG. 4 is a view showing various embodiments of the conductiveresistance sheets and peripheral parts thereof. Structures of theconductive resistance sheets are briefly illustrated in FIG. 2 , butwill be understood in detail with reference to FIG. 4 .

First, a conductive resistance sheet proposed in FIG. 4 a may bepreferably applied to the main body-side vacuum adiabatic body.Specifically, the first and second plate members 10 and 20 are to besealed so as to vacuumize the interior of the vacuum adiabatic body. Inthis case, since the two plate members have different temperatures fromeach other, heat transfer may occur between the two plate members. Aconductive resistance sheet 60 is provided to prevent heat conductionbetween two different kinds of plate members.

The conductive resistance sheet 60 may be provided with sealing parts 61at which both ends of the conductive resistance sheet 60 are sealed todefine at least one portion of the wall for the third space and maintainthe vacuum state. The conductive resistance sheet 60 may be provided asa thin foil in units of micrometers so as to reduce the amount of heatconducted along the wall for the third space. The sealing parts 61 maybe provided as welding parts. That is, the conductive resistance sheet60 and the plate members 10 and 20 may be fused to each other. In orderto cause a fusing action between the conductive resistance sheet 60 andthe plate members 10 and 20, the conductive resistance sheet 60 and theplate members 10 and 20 may be made of the same material, and astainless material may be used as the material. The sealing parts 61 arenot limited to the welding parts, and may be provided through a processsuch as cocking. The conductive resistance sheet 60 may be provided in acurved shape. Thus, a heat conduction distance of the conductiveresistance sheet 60 is provided longer than the linear distance of eachplate member, so that the amount of heat conduction can be furtherreduced.

A change in temperature occurs along the conductive resistance sheet 60.Therefore, in order to block heat transfer to the exterior of theconductive resistance sheet 60, a shielding part (shield) 62 may beprovided at the exterior of the conductive resistance sheet 60 such thatan adiabatic action occurs. In other words, in the refrigerator, thesecond plate member 20 has a high temperature and the first plate member10 has a low temperature. In addition, heat conduction from hightemperature to low temperature occurs in the conductive resistance sheet60, and hence the temperature of the conductive resistance sheet 60 issuddenly changed. Therefore, when the conductive resistance sheet 60 isopened to the exterior thereof, heat transfer through the opened placemay seriously occur. In order to reduce heat loss, the shielding part 62is provided at the exterior of the conductive resistance sheet 60. Forexample, when the conductive resistance sheet 60 is exposed to any oneof the low-temperature space and the high-temperature space, theconductive resistance sheet 60 does not serve as a conductive resistoras well as the exposed portion thereof, which is not preferable.

The shielding part 62 may be provided as a porous material contacting anouter surface of the conductive resistance sheet 60. The shielding part62 may be provided as an adiabatic structure, e.g., a separate gasket,which is placed at the exterior of the conductive resistance sheet 60.The shielding part 62 may be provided as a portion of the vacuumadiabatic body, which is provided at a position facing a correspondingconductive resistance sheet 60 when the main body-side vacuum adiabaticbody is closed with respect to the door-side vacuum adiabatic body. Inorder to reduce heat loss even when the main body and the door areopened, the shielding part 62 may be preferably provided as a porousmaterial or a separate adiabatic structure.

A conductive resistance sheet proposed in FIG. 4 b may be preferablyapplied to the door-side vacuum adiabatic body. In FIG. 4 b , portionsdifferent from those of FIG. 4 a are described in detail, and the samedescription is applied to portions identical to those of FIG. 4 a . Aside frame 70 is further provided at an outside of the conductiveresistance sheet 60. A part for sealing between the door and the mainbody, an exhaust port necessary for an exhaust process, a getter portfor vacuum maintenance, and the like may be placed on the side frame 70.This is because the mounting of parts is convenient in the mainbody-side vacuum adiabatic body, but the mounting positions of parts arelimited in the door-side vacuum adiabatic body.

In the door-side vacuum adiabatic body, it is difficult to place theconductive resistance sheet 60 at a front end portion of the vacuumspace part, i.e., a corner side portion of the vacuum space part. Thisis because, unlike the main body, a corner edge portion of the door isexposed to the exterior. More specifically, if the conductive resistancesheet 60 is placed at the front end portion of the vacuum space part,the corner edge portion of the door is exposed to the exterior, andhence there is a disadvantage in that a separate adiabatic part shouldbe configured so as to heat-insulate the conductive resistance sheet 60.

A conductive resistance sheet proposed in FIG. 4 c may be preferablyinstalled in the pipeline passing through the vacuum space part. In FIG.4 c , portions different from those of FIGS. 4 a and 4 b are describedin detail, and the same description is applied to portions identical tothose of FIGS. 4 a and 4 b . A conductive resistance sheet having thesame shape as that of FIG. 4 a , preferably, a wrinkled conductiveresistance sheet 63 (or folded conductive resistance sheet) may beprovided at a peripheral portion of the pipeline 64. Accordingly, a heattransfer path can be lengthened, and deformation caused by a pressuredifference can be prevented. In addition, a separate shielding part maybe provided to improve the adiabatic performance of the conductiveresistance sheet.

A heat transfer path between the first and second plate members 10 and20 will be described with reference back to FIG. 4 a . Heat passingthrough the vacuum adiabatic body may be divided into surface conductionheat ① conducted along a surface of the vacuum adiabatic body, morespecifically, the conductive resistance sheet 60, supporter conductionheat ② conducted along the supporting unit 30 provided inside the vacuumadiabatic body, gas conduction heat (convection) ③ conducted through aninternal gas in the vacuum space part, and radiation transfer heat ④transferred through the vacuum space part.

The transfer heat may be changed depending on various depending onvarious design dimensions. For example, the supporting unit may bechanged such that the first and second plate members 10 and 20 canendure a vacuum pressure without being deformed, the vacuum pressure maybe changed, the distance between the plate members may be changed, andthe length of the conductive resistance sheet may be changed. Thetransfer heat may be changed depending on a difference in temperaturebetween the spaces (the first and second spaces) respectively providedby the plate members. In the embodiment, a preferred configuration ofthe vacuum adiabatic body has been found by considering that its totalheat transfer amount is smaller than that of a typical adiabaticstructure formed by foaming polyurethane. In a typical refrigeratorincluding the adiabatic structure formed by foaming the polyurethane, aneffective heat transfer coefficient may be proposed as 19.6 mW/mK.

By performing a relative analysis on heat transfer amounts of the vacuumadiabatic body of the embodiment, a heat transfer amount by the gasconduction heat ③ can become smallest. For example, the heat transferamount by the gas conduction heat ③ may be controlled to be equal to orsmaller than 4% of the total heat transfer amount. A heat transferamount by solid conduction heat defined as a sum of the surfaceconduction heat ① and the supporter conduction heat ② is largest. Forexample, the heat transfer amount by the solid conduction heat may reach75% of the total heat transfer amount. A heat transfer amount by theradiation transfer heat ④ is smaller than the heat transfer amount bythe solid conduction heat but larger than the heat transfer amount ofthe gas conduction heat ③. For example, the heat transfer amount by theradiation transfer heat ④ may occupy about 20% of the total heattransfer amount.

According to such a heat transfer distribution, effective heat transfercoefficients (eK: effective K) (W/mK) of the surface conduction heat ①,the supporter conduction heat ②, the gas conduction heat ③, and theradiation transfer heat ④ may have an order of Equation 1.

eK_(solid conduction heat) > eK_(radiation transfer heat) > eK_(gas conduction heat)

Here, the effective heat transfer coefficient (eK) is a value that canbe measured using a shape and temperature differences of a targetproduct. The effective heat transfer coefficient (eK) is a value thatcan be obtained by measuring a total heat transfer amount and atemperature at least one portion at which heat is transferred. Forexample, a calorific value (W) is measured using a heating source thatcan be quantitatively measured in the refrigerator, a temperaturedistribution (K) of the door is measured using heat respectivelytransferred through a main body and an edge of the door of therefrigerator, and a path through which heat is transferred is calculatedas a conversion value (m), thereby evaluating an effective heat transfercoefficient.

The effective heat transfer coefficient (eK) of the entire vacuumadiabatic body is a value given by k=QL/A_(Δ)T. Here, Q denotes acalorific value (W) and may be obtained using a calorific value of aheater. A denotes a sectional area (m²) of the vacuum adiabatic body, Ldenotes a thickness (m) of the vacuum adiabatic body, and _(Δ)T denotesa temperature difference.

For the surface conduction heat, a conductive calorific value may beobtained through a temperature difference (_(Δ)T) between an entranceand an exit of the conductive resistance sheet 60 or 63, a sectionalarea (A) of the conductive resistance sheet, a length (L) of theconductive resistance sheet, and a thermal conductivity (k) of theconductive resistance sheet (the thermal conductivity of the conductiveresistance sheet is a material property of a material and can beobtained in advance). For the supporter conduction heat, a conductivecalorific value may be obtained through a temperature difference (_(Δ)T)between an entrance and an exit of the supporting unit 30, a sectionalarea (A) of the supporting unit, a length (L) of the supporting unit,and a thermal conductivity (k) of the supporting unit. Here, the thermalconductivity of the supporting unit is a material property of a materialand can be obtained in advance. The sum of the gas conduction heat ③,and the radiation transfer heat ④ may be obtained by subtracting thesurface conduction heat and the supporter conduction heat from the heattransfer amount of the entire vacuum adiabatic body. A ratio of the gasconduction heat ③, and the radiation transfer heat ④ may be obtained byevaluating radiation transfer heat when no gas conduction heat exists byremarkably lowering a vacuum degree of the vacuum space part 50.

When a porous material is provided inside the vacuum space part 50,porous material conduction heat ⑤ may be a sum of the supporterconduction heat ② and the radiation transfer heat ④. The porous materialconduction heat ⑤ may be changed depending on various variablesincluding a kind, an amount, and the like of the porous material.

According to an embodiment, a temperature difference _(Δ)T₁ between ageometric center formed by adjacent bars 31 and a point at which each ofthe bars 31 is located may be preferably provided to be less than 0.5°C. Also, a temperature difference _(A)T₂ between the geometric centerformed by the adjacent bars 31 and an edge portion of the vacuumadiabatic body may be preferably provided to be less than 0.5° C. In thesecond plate member 20, a temperature difference between an averagetemperature of the second plate and a temperature at a point at which aheat transfer path passing through the conductive resistance sheet 60 or63 meets the second plate may be largest. For example, when the secondspace is a region hotter than the first space, the temperature at thepoint at which the heat transfer path passing through the conductiveresistance sheet meets the second plate member becomes lowest.Similarly, when the second space is a region colder than the firstspace, the temperature at the point at which the heat transfer pathpassing through the conductive resistance sheet meets the second platemember becomes highest.

This means that the amount of heat transferred through other pointsexcept the surface conduction heat passing through the conductiveresistance sheet should be controlled, and the entire heat transferamount satisfying the vacuum adiabatic body can be achieved only whenthe surface conduction heat occupies the largest heat transfer amount.To this end, a temperature variation of the conductive resistance sheetmay be controlled to be larger than that of the plate member.

Physical characteristics of the parts constituting the vacuum adiabaticbody will be described. In the vacuum adiabatic body, a force by vacuumpressure is applied to all of the parts. Therefore, a material having astrength (N/m²) of a certain level may be preferably used.

Under such circumferences, the plate members 10 and 20 and the sideframe 70 may be preferably made of a material having a sufficientstrength with which they are not damaged by even vacuum pressure. Forexample, when the number of bars 31 is decreased so as to limit thesupport conduction heat, deformation of the plate member occurs due tothe vacuum pressure, which may be a bad influence on the externalappearance of refrigerator. The radiation resistance sheet 32 may bepreferably made of a material that has a low emissivity and can beeasily subjected to thin film processing. Also, the radiation resistancesheet 32 is to ensure a strength high enough not to be deformed by anexternal impact. The supporting unit 30 is provided with a strength highenough to support the force by the vacuum pressure and endure anexternal impact, and is to have machinability. The conductive resistancesheet 60 may be preferably made of a material that has a thin plateshape and can endure the vacuum pressure.

In an embodiment, the plate member, the side frame, and the conductiveresistance sheet may be made of stainless materials having the samestrength. The radiation resistance sheet may be made of aluminum havinga weaker strength that the stainless materials. The supporting unit maybe made of resin having a weaker strength than the aluminum.

Unlike the strength from the point of view of materials, analysis fromthe point of view of stiffness is required. The stiffness (N/m) is aproperty that would not be easily deformed. Although the same materialis used, its stiffness may be changed depending on its shape. Theconductive resistance sheets 60 or 63 may be made of a material having astrength, but the stiffness of the material is preferably low so as toincrease heat resistance and minimize radiation heat as the conductiveresistance sheet is uniformly spread without any roughness when thevacuum pressure is applied. The radiation resistance sheet 32 requires astiffness of a certain level so as not to contact another part due todeformation. Particularly, an edge portion of the radiation resistancesheet may generate conduction heat due to drooping caused by theself-load of the radiation resistance sheet. Therefore, a stiffness of acertain level is required. The supporting unit 30 requires a stiffnesshigh enough to endure a compressive stress from the plate member and anexternal impact.

In an embodiment, the plate member and the side frame may preferablyhave the highest stiffness so as to prevent deformation caused by thevacuum pressure. The supporting unit, particularly, the bar maypreferably have the second highest stiffness. The radiation resistancesheet may preferably have a stiffness that is lower than that of thesupporting unit but higher than that of the conductive resistance sheet.The conductive resistance sheet may be preferably made of a materialthat is easily deformed by the vacuum pressure and has the loweststiffness.

Even when the porous material 33 is filled in the vacuum space part 50,the conductive resistance sheet may preferably have the loweststiffness, and the plate member and the side frame may preferably havethe highest stiffness.

FIG. 5 is a view illustrating in detail a vacuum adiabatic bodyaccording to an embodiment. The embodiment proposed in FIG. 5 may bepreferably applied to the door-side vacuum adiabatic body, and thedescription of the vacuum adiabatic body shown in FIG. 4 b among thevacuum adiabatic bodies shown in FIG. 4 may be applied to portions towhich specific descriptions are not provided.

Referring to FIG. 5 , both end portions of the vacuum adiabatic body isheat-insulated by a separate product made of, for example, foamingurethane or Styrofoam, and an inside, i.e., a middle portion of thevacuum adiabatic body is heat-insulated in a vacuum state. The vacuumadiabatic body of this embodiment includes a first plate member 10providing a wall for a low-temperature space, a second plate member 20providing a wall for a high-temperature space, and a vacuum space part50 defined as a gap part (gap or space) between the first plate member10 and the second plate member 20. Also, the vacuum adiabatic bodyincludes a conductive resistance sheet 60 for blocking heat conductionbetween the first and second plate members 10 and 20. Also, the vacuumadiabatic body includes a side frame 70 fastened to the conductiveresistance sheet 60 and the second plate member 20 to provide a wall forone portion of the vacuum space part 50. Fastening parts of the sideframe 70 may be formed through welding. A supporting unit 30 capable ofmaintaining a gap of the vacuum space part 50 may be provided inside thevacuum space part 50.

A peripheral adiabatic part (or peripheral adiabatic mold) 90 isprovided at a peripheral portion, i.e., an outer edge portion of thevacuum adiabatic body, to improve the adiabatic performance of the edgeportion of the vacuum adiabatic body, which is weak to heat insulation.The peripheral adiabatic part 90 includes at least an outer surface ofthe conductive resistance sheet 60, thereby providing an adiabaticeffect. Accordingly, an inner surface of the conductive resistance sheet60 can be heat-insulated by the vacuum space part 50, and the outersurface of the conductive resistance sheet 50 can be heat-insulated bythe peripheral adiabatic part 90. As already described above, a suddenchange in temperature occurs in the conductive resistance sheet 60, andhence it is further required to reduce adiabatic loss through the outersurface of the conductive resistance sheet 60.

The adiabatic performance of the peripheral adiabatic part 90 may beimproved by a separate adiabatic member made of, for example, foamingurethane or Styrofoam. An inner panel 85 may provide a boundary to aninner portion of the peripheral adiabatic part 90. A separate structuremay be added to allow the inner panel 85 to be fixed to the second platemember 20. The inner panel 85 can protect not only the boundary of theperipheral adiabatic part 90 but also an inner portion of the vacuumadiabatic body.

The peripheral adiabatic part 90 may be placed in a region defined as aninside of the inner panel 85, the second plate member 20, the side frame70, the conductive resistance sheet 60, and the first plate member 10. Agroove 79 (or recess) may be provided at an edge of the inner panel 85,and a gasket 80 may be fixed into the groove 79.

The gasket 80 is a part that enables the first space to beheat-insulated from a second space, and temperatures of both the firstand second spaces with respect to the gasket 80 may be different fromeach other. Similarly, temperatures of both left and right sides of theinner panel 85 with respect to the gasket 80 may be different from eachother. This has influence on a change in temperature of an inside of theperipheral adiabatic part 90 and adiabatic performance due to the changein temperature, in addition to that temperatures of both left and rightsides of the conductive resistance sheet 60 are different from eachother. Isothermal lines inside the peripheral adiabatic body 90preferably have intervals as equal as possible so as to resist heattransfer through the inside of the peripheral adiabatic part 90.

In order to obtain such an effect, a place at which the gasket 80 islocated and a place at which the conductive resistance sheet 60 islocated are preferably opposite to each other in the vertical directionwith the peripheral adiabatic part 90 interposed therebetween. Accordingto the above-described configuration, the isothermal lines passingthrough the peripheral adiabatic part 90 can be provided at relativelyequal intervals.

More accurately, at least one portion of the conductive resistance sheet60 may be disposed inside a projection region in which projection isperformed toward a third space from the region in which the gasket 80 isprovided. For example, as illustrated in FIG. 5 , a projection orprotrusion is formed on the inner panel 85 to accommodate the gasket.The projection may protrude toward the vacuum space formed by the firstand second plate members 10, 20. Also, the conductive resistance sheet60 may be disposed at a place biased to an edge of the vacuum adiabaticbody from the projection region. For example, as illustrated in FIG. 5 ,the conductive resistance sheet 60 vertically overlaps the projection,while being biased toward an outside portion of the protrusion (e.g.,toward the outer edge). Accordingly, a path of heat transfer can belengthened, so that the adiabatic efficiency of the vacuum adiabaticbody can be further improved.

FIG. 6 illustrates temperature distribution curves with respect topositions of the conductive resistance sheet. FIG. 6(a) illustrates acase where the conductive resistance sheet is located biased to an innerdirection of the vacuum adiabatic body while being located in theprojection region. FIG. 6(b) illustrates a case where the conductiveresistance sheet is placed in the first space. FIG. 6(c) illustrates acase where the conductive resistance sheet is located biased to the edgepf the vacuum adiabatic body while being located in the projectionregion. FIG. 6(d) illustrates a case where the conductive resistancesheet is located biased to the inside of the vacuum adiabatic body whilebeing out of the projection region.

Paths of heat transfer will be described in detail with reference toFIG. 6 .

In the case of FIG. 6(b), heat infiltration into the conductiveresistance sheet is severe, and therefore, degradation of adiabaticperformance is severe. In the case of FIG. 6(b), reduction in adiabaticloss through a region out of the first space to reach the conductiveresistance sheet as one portion of the first plate member 10 andinfiltration of cold air into the peripheral adiabatic part 90 aresevere, which is not preferable.

When comparing the cases of FIGS. 6(a) and 6(c), a path of heattransfer, considered using a vertical line of isothermal lines, islengthened in the case of FIG. 6(c). In other words, the path of heattransfer is represented as a path of an upwardly convex parabola. Thus,the path of heat transfer can be lengthened. On the other hand, in thecase of FIG. 6(a), only a path of heat transfer provides only a path inone direction such as a right upward direction or a left upwarddirection.

Thus, the path of heat transfer is further lengthened in the case ofFIG. 6 , thereby obtaining an increase in adiabatic effect. However, theadiabatic performance may be changed through various modifications ofdesigns, numerical values, and the like.

Referring back to FIG. 5 , the side frame 70 is provided at the outsideof the conductive resistance sheet 60. The side frame 70 includes afirst fastening part (or first portion/section) 74 as a part fastened tothe conductive resistance sheet 60, a gap part (or secondportion/section or connection wall) 73 extending downward from the firstfastening part 74, i.e., toward the second plate member 20, and anextending part (or third portion/section) 72 bent from the gap part 73to extend outward along an inner surface of the second plate member 20.An end portion of the extending part 72 may extend up to an edge of afront portion of the vacuum adiabatic body, and a second fastening part(or seal, joint, weld) 71 of the extending part 72 may be fastened tothe second plate member 20 at the end portion of the extending part 72.

The second fastening part 71 may be provided through welding so as tomaintain its sealing performance. In this case, a small deformation mayoccur in the second plate member 20 due to high-temperature heatgenerated in the welding. However, the second fastening part 71 is notprovided at a front portion of the second plate member 20 but providedat an edge of the front portion or a side portion of the second platemember 20. Hence, the second fastening part 71 is not viewed by a user.In addition, formation of dews may occur on an outer surface of thesecond plate member 20, corresponding to the second fastening part 71,due to a difference in temperature between the end portion of theextending part 72 and the second plate member 20. The formation of dewmay occur when the second space is in a state of high temperature andhigh humidity and the first space is in a state of low temperature.However, since the second fastening part 71 is not provided at the frontportion of the second plate member 20 but provided at the edge of thefront portion or the side portion of the second plate member 20, theformation of dew is not visible to the user. Thus, any separate memberfor covering the outer surface of the second plate member 20 is notrequired.

The extending part 72 extends along the inner surface of the secondplate member 20. The extending part 72 may at least partially contactthe second plate member 20 to reinforce the strength of an outer wall ofthe vacuum adiabatic body. Thus, it is possible to prevent deformationof the outer surface of the vacuum adiabatic body and to increase theflatness of the outer surface.

FIG. 7 is an exploded perspective view of a vacuum adiabatic bodyaccording to an embodiment.

Referring to FIG. 7 , there is provided a vacuum adiabatic assembly 21including a first plate member 10 and a second plate member 20. A gappart between the first plate member 10 and the second plate member 20forms a vacuum space part 50. The first plate member 10 is provided atone portion of an inner surface of the second plate member 20, and aregion in which the first plate member 10 is not provided may beheat-insulated by a peripheral adiabatic part 90. A getter port 41 maybe provided at a predetermined position of the first plate member 10. Aside frame 70 may extend up to an outer circumferential portion of thesecond plate member 20 by an extending part 72. A second fastening part71 is provided at an end portion of the extending part 72.

An inner panel 85 is provided inside the peripheral adiabatic part 90,and a basket 86 is mounted to be supported to the inner panel 85 oranother product. The basket 86 may be provided to be larger as thevacuum adiabatic body is provided.

Referring to a view comparing performances, proposed in FIG. 12 , it canbe seen that as the vacuum adiabatic body is provided, a width of thebasket 86 is increased from W1 to W2. Accordingly, the internal volumeof the refrigerator can be increased. The view proposed in FIG. 12illustrates a door-in-door refrigerator in which storage goods can beobtained without opening the entire internal space of the refrigerator.In other words, the view proposed in FIG. 12 illustrates a case wherethe vacuum adiabatic body is used as an outer door of the refrigerator.In this case, the volume of storage goods that can be stored through theouter door can be increased, so that user’s convenience can be furtherimproved.

Referring back to FIG. 7 , a gasket 80 coupled to the inner panel 85 isprovided, and a latch 88 capable of changing a lock state of the doormay be further provided. The latch 88 may be fixed to an inside of theperipheral adiabatic part 90. In addition, an upper hinge 87 and a lowerhinge 86 are fixed to the inner panel 85, and an upper cover 83 and alower cover 81 may be provided to protect upper and lower sides of thevacuum adiabatic body, respectively.

According to this embodiment, after the vacuum adiabatic assembly 21 ismanufactured, the vacuum adiabatic body can be produced using productionequipment using the typical foaming urethane as it is. In other words,the door of the refrigerator, provided as the vacuum adiabatic body, canbe manufactured using the existing refrigerator manufacturing equipmentas it is.

Also, various parts required to operate the door can be convenientlymounted to the peripheral adiabatic part 90 and the inner panel 85covering the peripheral adiabatic part 90.

Also, as the side frame 70 extends up to the edge of the second platemember 20, the strength of the vacuum adiabatic assembly 21 can bereinforced, so that the vacuum adiabatic body can be stably used evenwhen various additions are further provided.

In addition, no formation of dews or no welding line is viewed by theuser, so that a high-quality product can be provided. Furthermore, theinternal volume of the door can be increased by the effect of the vacuumspace part 50 placed between the first plate member and the second platemember.

Hereinafter, a vacuum pressure preferably determined depending on aninternal state of the vacuum adiabatic body. As already described above,a vacuum pressure is to be maintained inside the vacuum adiabatic bodyso as to reduce heat transfer. At this time, it will be easily expectedthat the vacuum pressure is preferably maintained as low as possible soas to reduce the heat transfer.

The vacuum space part may resist the heat transfer by applying only thesupporting unit 30. Alternatively, the porous material 33 may be filledtogether with the supporting unit in the vacuum space part 50 to resistthe heat transfer. Alternatively, the vacuum space part may resist theheat transfer not by applying the supporting unit but by applying theporous material 33.

The case where only the supporting unit is applied will be described.

FIG. 8 illustrates graphs showing changes in adiabatic performance andchanges in gas conductivity with respect to vacuum pressures by applyinga simulation.

Referring to FIG. 8 , it can be seen that, as the vacuum pressure isdecreased, i.e., as the vacuum degree is increased, a heat load in thecase of only the main body (Graph 1) or in the case where the main bodyand the door are joined together (Graph 2) is decreased as compared withthat in the case of the typical product formed by foaming polyurethane,thereby improving the adiabatic performance. However, it can be seenthat the degree of improvement of the adiabatic performance is graduallylowered. Also, it can be seen that, as the vacuum pressure is decreased,the gas conductivity (Graph 3) is decreased. However, it can be seenthat, although the vacuum pressure is decreased, the ratio at which theadiabatic performance and the gas conductivity are improved is graduallylowered. Therefore, it is preferable that the vacuum pressure isdecreased as low as possible. However, it takes long time to obtainexcessive vacuum pressure, and much cost is consumed due to excessiveuse of a getter. In the embodiment, an optimal vacuum pressure isproposed from the above-described point of view.

FIG. 9 illustrates graphs obtained by observing, over time and pressure,a process of exhausting the interior of the vacuum adiabatic body whenthe supporting unit is used.

Referring to FIG. 9 , in order to create the vacuum space part 50 to bein the vacuum state, a gas in the vacuum space part 50 is exhausted by avacuum pump while evaporating a latent gas remaining in the parts of thevacuum space part 50 through baking. However, if the vacuum pressurereaches a certain level or more, there exists a point at which the levelof the vacuum pressure is not increased any more (_(Δ)t1). After that,the getter is activated by disconnecting the vacuum space part 50 fromthe vacuum pump and applying heat to the vacuum space part 50 (_(Δ)t2).If the getter is activated, the pressure in the vacuum space part 50 isdecreased for a certain period of time, but then normalized to maintaina vacuum pressure of a certain level. The vacuum pressure that maintainsthe certain level after the activation of the getter is approximately1.8×10^(–6) Torr.

In the embodiment, a point at which the vacuum pressure is notsubstantially decreased any more even though the gas is exhausted byoperating the vacuum pump is set to the lowest limit of the vacuumpressure used in the vacuum adiabatic body, thereby setting the minimuminternal pressure of the vacuum space part 50 to 1.8 × 10^(–6) Torr.

FIG. 10 illustrates graphs obtained by comparing vacuum pressures andgas conductivities.

Referring to FIG. 10 , gas conductivities with respect to vacuumpressures depending on sizes of a gap in the vacuum space part 50 arerepresented as graphs of effective heat transfer coefficients (eK).Effective heat transfer coefficients (eK) were measured when the gap inthe vacuum space part 50 has three sizes of 2.76 mm, 6.5 mm, and 12.5mm. The gap in the vacuum space part 50 is defined as follows. When theradiation resistance sheet 32 exists inside vacuum space part 50, thegap is a distance between the radiation resistance sheet 32 and theplate member adjacent thereto. When the radiation resistance sheet 32does not exist inside vacuum space part 50, the gap is a distancebetween the first and second plate members.

It can be seen that, since the size of the gap is small at a pointcorresponding to a typical effective heat transfer coefficient of 0.0196W/mK, which is provided to a adiabatic material formed by foamingpolyurethane, the vacuum pressure is 2.65×10⁻¹ Torr even when the sizeof the gap is 2.76 mm. Meanwhile, it can be seen that the point at whichreduction in adiabatic effect caused by gas conduction heat is saturatedeven though the vacuum pressure is decreased is a point at which thevacuum pressure is approximately 4.5×10⁻³ Torr. The vacuum pressure of4.5×10⁻³ Torr can be defined as the point at which the reduction inadiabatic effect caused by gas conduction heat is saturated. Also, whenthe effective heat transfer coefficient is 0.1 W/mK, the vacuum pressureis 1.2×10⁻² Torr.

When the vacuum space part 50 is not provided with the supporting unitbut provided with the porous material, the size of the gap ranges from afew micrometers to a few hundreds of micrometers. In this case, theamount of radiation heat transfer is small due to the porous materialeven when the vacuum pressure is relatively high, i.e., when the vacuumdegree is low. Therefore, an appropriate vacuum pump is used to adjustthe vacuum pressure. The vacuum pressure appropriate to thecorresponding vacuum pump is approximately 2.0×10⁻⁴ Torr. Also, thevacuum pressure at the point at which the reduction in adiabatic effectcaused by gas conduction heat is saturated is approximately 4.7× 10⁻²Torr. Also, the pressure where the reduction in adiabatic effect causedby gas conduction heat reaches the typical effective heat transfercoefficient of 0.0196 W/mK is 730 Torr.

When the supporting unit and the porous material are provided togetherin the vacuum space part, a vacuum pressure may be created and used,which is middle between the vacuum pressure when only the supportingunit is used and the vacuum pressure when only the porous material isused.

FIG. 11 is a partial sectional view of a vacuum adiabatic body accordingto an embodiment.

The embodiment proposed in FIG. 11 is identical to the embodimentproposed in FIG. 5 , except that a conductive resistance adiabaticmaterial 91 (or conductive resistance adiabatic insulator or sheet) isprovided to further reduce heat loss through an outer surface of aconductive resistance sheet 60. The conductive resistance adiabaticmaterial 91 may be provided to cover at least one portion of a sideframe 70 and at least one portion of a first plate member 10 togetherwith the conductive resistance sheet 60. Thus, it is possible to furtherreduce heat conducted along the first plate member 10. When theconductive resistance adiabatic material 91 is provided, any peripheraladiabatic part 90 may not be additionally provided. However, as theperipheral adiabatic part 90 is provided, adiabatic efficiency can befurther improved, which is preferable.

Meanwhile, the conductive resistance adiabatic material 91 may furtherextend toward a first space while being out of the position at which theperipheral adiabatic part 90. Accordingly, it is possible to furtherreduce heat or cold air transferred to the conductive resistance sheet60 along the first plate member 10.

In the description of the present disclosure, a part for performing thesame action in each embodiment of the vacuum adiabatic body may beapplied to another embodiment by properly changing the shape ordimension of the another embodiment. Accordingly, still anotherembodiment can be easily proposed. For example, in the detaileddescription, in the case of a vacuum adiabatic body suitable as adoor-side vacuum adiabatic body, the vacuum adiabatic body may beapplied as a main body-side vacuum adiabatic body by properly changingthe shape and configuration of a vacuum adiabatic body.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

The vacuum adiabatic body proposed in the present disclosure may bepreferably applied to refrigerators. However, the application of thevacuum adiabatic body is not limited to the refrigerators, and may beapplied in various apparatuses such as cryogenic refrigeratingapparatuses, heating apparatuses, and ventilation apparatuses.

According to the present disclosure, the vacuum adiabatic body can beindustrially applied to various adiabatic apparatuses. The adiabaticeffect can be enhanced, so that it is possible to improve energy useefficiency and to increase the effective volume of an apparatus.

However, it is difficult to obtain an adiabatic effect of a practicallevel by providing the walls of the refrigerator to be in a sufficientvacuum state. Specifically, it is difficult to prevent heat transfer ata contact portion between external and internal cases having differenttemperatures. Further, it is difficult to maintain a stable vacuumstate. Furthermore, it is difficult to prevent deformation of the casesdue to a sound pressure in the vacuum state. Due to these problems, thetechnique of Reference Document 3 is limited to cryogenic refrigeratingapparatuses, and is not applied to refrigerating apparatuses used ingeneral households.

Embodiments provide a vacuum adiabatic body and a refrigerator, whichcan obtain a sufficient adiabatic effect in a vacuum state and beapplied commercially.

In one embodiment, a vacuum adiabatic body includes: a first platemember defining at least one portion of a wall for a first space; asecond plate member defining at least one portion of a wall for a secondspace having a different temperature from the first space; a sealingpart sealing the first plate member and the second plate member toprovide a third space that has a temperature between the temperature ofthe first space and the temperature of the second space and is in avacuum state; a supporting unit maintaining the third space; a heatresistance unit at least including a conductive resistance sheet capableof resisting heat conduction flowing along a wall for the third space todecrease a heat transfer amount between the first plate member and thesecond plate member; and an exhaust port through which a gas in thethird space is exhausted, wherein the vacuum adiabatic body furtherincludes a side frame fastened to the conductive resistance sheet andthe second plate member, and wherein the side frame is fastened to anedge portion of the second plate member.

The vacuum adiabatic body may include a conductive resistance adiabaticmaterial at least heat-insulating an outer surface of the conductiveresistance sheet, the conductive resistance adiabatic materialheat-insulating at least one portion of the side frame and at least oneportion of the first plate member.

The vacuum adiabatic body may include: a peripheral adiabatic partprovided to an outer wall of an edge portion of the third space toimprove the adiabatic performance of the edge portion of the thirdspace; and a conductive resistance adiabatic material at leastheat-insulating the outer surface of the conductive resistance sheet,the conductive resistance adiabatic material further extending towardthe first space while being out of the peripheral adiabatic part.

The side frame may include: a first fastening part fastened to theconductive resistance sheet; a gap part bent from the first fasteningpart to extend in a gap direction of the second space; an extending partbent from the gap part to extend outward along an inner surface of thesecond plate member; and a second fastening part fastened to the secondplate member. At least one portion of the extending part may contact theinner surface of the second plate member. A height of the gap part maybe equal to that of the third space. Each of the first and secondfastening parts may be provided as a welding part.

The vacuum adiabatic body may include a peripheral adiabatic partprovided at an outside of the outer wall of the edge portion of thethird space to improve the adiabatic performance of the edge portion ofthe third space. A heat transfer path of the peripheral adiabatic partmay be provided as a path of a parabola. The vacuum adiabatic body mayfurther include: an inner panel for protecting at least one portion ofthe peripheral adiabatic part; and a gasket fixed to the inner panel.The conductive resistance sheet may be provided at the opposite side ofthe gasket with the peripheral adiabatic part interposed therebetween.

In another embodiment, a vacuum adiabatic body includes: a first platemember defining at least one portion of a wall for a first space; asecond plate member defining at least one portion of a wall for a secondspace having a different temperature from the first space; a sealingpart sealing the first plate member and the second plate member toprovide a third space that has a temperature between the temperature ofthe first space and the temperature of the second space and is in avacuum state; a supporting unit maintaining the third space; a heatresistance unit including at least one conductive resistance sheet todecrease a heat transfer amount between the first plate member and thesecond plate member, wherein the at least one conductive resistancesheet is thinner than each of the first and second plate members andprovided as a curved surface to resist heat conduction flowing along awall for the third space; and a side frame fastened to the conductiveresistance sheet and the second plate member.

A change in temperature of the conductive resistance sheet may be moresevere than that of each of the first and second plate members. Theconductive resistance sheet may define, together with each of the firstand second plate members, at least one portion of the wall for the thirdspace, and have at least one curved part. The conductive resistancesheet may have a lower stiffness than each of the first and second platemembers and the supporting unit. The vacuum adiabatic body may furtherinclude: a peripheral adiabatic part provided at an outside an edgeportion of the third space to improve the adiabatic performance of theedge portion of the third space; an inner panel for protecting at leastone portion of the peripheral adiabatic part; and a gasket fixed to theinner panel. The conductive resistance sheet may be provided at theopposite side of the gasket with the peripheral adiabatic partinterposed therebetween. At least one portion of the conductiveresistance sheet may be placed in a projection region in whichprojection is performed toward the third space from a region in whichthe gasket is provided. The conductive resistance sheet may be placedbiased to an edge of the vacuum adiabatic body in the projection region.

A vacuum degree (or pressure) of the third space may be equal to orgreater than 1.8×10⁻⁶ Torr and equal to or smaller than 4.5×10⁻³ Torr.

In still another embodiment, a refrigerator includes: a main bodyprovided with an internal space in which storage goods are stored; and adoor provided to open/close the main body from an external space,wherein, in order to supply a refrigerant into the main body, therefrigerator includes: a compressor for compressing the refrigerant; acondenser for condensing the compressed refrigerant; an expander forexpanding the condensed refrigerant; and an evaporator for evaporatingthe expanded refrigerant to take heat, wherein the door includes avacuum adiabatic body, wherein the vacuum adiabatic body includes: afirst plate member defining at least one portion of a wall for theinternal space; a second plate member defining at least one portion of awall for the external space; a sealing part sealing the first platemember and the second plate member to provide a vacuum space part thathas a temperature between a temperature of the internal space and atemperature of the external space and is in a vacuum state; a supportingunit maintaining the vacuum space part; a heat resistance unit at leastincluding a conductive resistance sheet capable of resisting heatconduction flowing along a wall for the third space to decrease a heattransfer amount between the first plate member and the second platemember; and an exhaust port through which a gas in the vacuum space partis exhausted, wherein the vacuum adiabatic body further includes: a sideframe fastened to the conductive resistance sheet and the second platemember; and a conductive resistance adiabatic material heat-insulatingan outer surface of the conductive resistance sheet, at least oneportion of the side frame, and at least one portion of the first platemember.

The refrigerator may include a peripheral adiabatic part provided to anouter wall of an edge portion of the vacuum space part to improve theadiabatic performance of the edge portion of the vacuum space part. Theside frame may include: a first fastening part fastened to theconductive resistance sheet; a gap part bent from the first fasteningpart to extend in a gap direction of the second space; an extending partbent from the gap part to extend outward along an inner surface of thesecond plate member; and a second fastening part fastened to the secondplate member. The side frame may be fastened to a side portion of thevacuum adiabatic body.

According to the present disclosure, it is possible to a sufficientvacuum adiabatic effect. According to the present disclosure, it ispossible to prevent the formation of dews at the door and to improve theadiabatic performance of an edge portion of the vacuum adiabatic body.Also, it is possible to increase the internal accommodation volume of anouter door in a door-in-door refrigerator.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features will be apparent fromthe description and drawings, and from the claims.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A vacuum adiabatic body comprising: a firstplate; a second plate; a vacuum space provided between the first plateand the second plate, the vacuum space to be provided in a vacuum state;a side frame to define at least one portion of the wall for the vacuumspace the side frame extending in a direction of a thickness of thevacuum space; and a conductive resistance sheet disposed to be connectedwith the first plate and configured to reduce heat conduction betweenthe first plate and the second plate, wherein the first plate, theconductive resistance sheet and the side frame are positionedsequentially.
 2. The vacuum adiabatic body according to claim 1, whereinthe side frame comprises: a first fastening part sealably fastened tothe conduction resistance sheet; and a second fastening part fastened tothe second plate.
 3. The vacuum adiabatic body according to claim 2,wherein the side frame further comprises a gap part extending from thefirst fastening part toward the second plate.
 4. The vacuum adiabaticbody according to claim 3, wherein at least one portion of the gap partis formed by bending from the first fastening part.
 5. The vacuumadiabatic body according to claim 3, wherein a height of the gap part isequal to that of the vacuum space.
 6. The vacuum adiabatic bodyaccording to claim 3, wherein the side frame further comprises anextending part extending between the gap part and the second plate. 7.The vacuum adiabatic body according to claim 6, wherein the extendingpart is formed by bending at one end of the gap part.
 8. The vacuumadiabatic body according to claim 6, wherein the extending part extendsalong the inner surface of the second plate.
 9. A vacuum adiabatic bodycomprising: a first plate; a second plate; a vacuum space providedbetween the first plate and the second plate, the vacuum space to beprovided in a vacuum state; a side frame to define at least one portionof the wall for the vacuum space the side frame extending in a directionof a thickness of the vacuum space; and a conductive resistance sheetdisposed to be connected with the first plate and configured to reduceheat conduction between the first plate and the second plate, whereinthe conductive resistance sheet and the side frame is disposed betweenthe first plate and the second plate.
 10. The vacuum adiabatic bodyaccording to claim 9, further comprising a peripheral adiabatic moldprovided adjacent to an outer wall at a distal end region of the vacuumspace to improve adiabatic performance at the distal end region of thevacuum space.
 11. The vacuum adiabatic body according to claim 10,further comprising a conductive resistance adiabatic material providedover an outer surface of the conductive resistance sheet, wherein atleast a portion of the conductive resistance adiabatic material extendstoward the first plate and away from the peripheral adiabatic mold. 12.The vacuum adiabatic body according to claim 9, wherein the side frameis thicker than the conductive resistance sheet.
 13. The vacuumadiabatic body according to claim 9, wherein the side frame is made ofmetal.
 14. The vacuum adiabatic body according to claim 9, wherein avacuum pressure of the vacuum space is equal to or greater than 1.8×10⁻⁶Torr and equal to or smaller than 4.5×10⁻³ Torr.
 15. A vacuum adiabaticbody comprising: a first plate; a second plate; a vacuum space providedbetween the first plate and the second plate, the vacuum space to beprovided in a vacuum state; a side frame to define at least one portionof the wall for the vacuum space the side frame extending in a directionof a thickness of the vacuum space; and a conductive resistance sheetdisposed to be connected with the first plate and configured to reduceheat conduction between the first plate and the second plate, whereinone end of the conductive resistance sheet is sealed at one side of theside frame.
 16. The vacuum adiabatic body according to claim 15, whereinthe other end of the conductive resistance sheet is sealed at one sideof the first plate.
 17. The vacuum adiabatic body according to claim 16,wherein the conductive resistance sheet defines, together with each ofthe first and second plates, at least a portion of the wall adjacent thevacuum space, and has at least one curved portion.
 18. A vacuumadiabatic body comprising: a first plate; a second plate; a vacuum spaceprovided between the first plate and the second plate, the vacuum spaceto be provided in a vacuum state; a side frame to define at least oneportion of the wall for the vacuum space the side frame extending in adirection of a thickness of the vacuum space; and a conductiveresistance sheet disposed to be connected with the first plate andconfigured to reduce heat conduction between the first plate and thesecond plate, wherein the side frame comprises: a first fastening partsealably fastened to the conduction resistance sheet; and a secondfastening part fastened to the second plate.
 19. The vacuum adiabaticbody according to claim 18, further comprising a peripheral adiabaticmold provided adjacent to an outer wall at a distal end region of thevacuum space to improve adiabatic performance at the distal end regionof the vacuum space.
 20. The vacuum adiabatic body according to claim19, further comprising an inner panel that protects at least one portionof the peripheral adiabatic mold.
 21. The vacuum adiabatic bodyaccording to claim 20, further comprising a gasket fixed to the innerpanel.